i searched but could not find much info.

I installed new front axxis ultimate brake pads.

I noticed when I drive that the front pads seem to be rubbing the rotor while I am driving, very slightly, noticeable at low speeds.

Even when I am not braking they make a small amount of noise.

I put the car in the air and noticed that rear pads seem to touch as well and make a small amount of noise when i turn the wheel.

Is it normal for pads to SLIGHTLY touch when not braking?

Could it be that the axxis pads make a rubbing noise that is more noticeable than the stock pads?

any help is appreciated

thanks!

It's normal for disc brake pads to make constant contact with the rotor surface, unlike drum brakes. Drum brakes have springs that retract the brake shoes away from the drums when you lift off the brake pedal. On a disc brake car, the pedal returns to rest in the up position but the calipers don't utilize any method of retracting the pads or caliper pistons (pots). That's why we often have to manually push the pistons back into the caliper body when replacing well worn pads.

I'm a little surprised that you can actually hear the brakes when you're not pressing on the brake pedal, though. Ultimates and other more aggressive race pads are noisier (tarmac pads in WRC cars are horrendously loud), but as long as you can freely spin the wheels when the vehicle is raised off the ground, I wouldn't be concerned.

Thank you wingless wonder, I was pretty sure that everything was OK, but your words gave me confidence.

I went out to the track today, Buttonwillow, no problems.

Everything went well, rotors/pads were not overheating due to rubbing.

I guess i'm just not used to running "track pads", it was my first time. The noise threw me off.


-A

its actualy not normal for the pads to touch( at least not noticable) if they were drums its normal. Did you compress the pistons back in when you changed your pads out?

to explain myself its true that the calipers dont use a real method of retraction but they should move back some due to the pressure being taken off of the piston(s). so there really shouldnt be any noise if you use a normal pad race pads i dont know about but everyday street pads they should move far enough off to make VERY little noise most deff not a noticable noise, this light contact is why pads glaze which is normal so dont let a brake service store tell you you have a problem with your car cause of glazed pads. Drum brakes DO have retracting springs but they pivot at either the bottom or the top (depending on the type of drum they are) and they DO touch the drum at that point they have to or else the parking brake wont be adjusted correctly and wont work right. check the piston and I dont know this yet but if the calipers used in the WRX are floating calipers you need to change the caliper sliding pins and the rubble sleeve EVERY TIME you do a brake service to your car (0r at least you should it keeps the floating side mobile so that it can slide and contact the rotor.) If it is a fixed caliper depress the pistons on BOTH sides. and as always use lock tite on the bolts holding the calliper to the car.

and one more thing the piston will always need to be pressed back in its the brake fluid pressure that pusehes it out and it will continue to move out to adjust for the wear of the pad. so much so that if your pads are rivited it will dig the rivets into the rotor.

oh and lastly did you resurface the rotors that could be it too...sorry so many posts just going over the touble shooting in my head for a brake job and things keep popping up.

Constant Contact with the rotor is normal. Pads travel a very short distance. BMWs utilize constant contact to keep the rotors warm to provide better braking in wet conditions.

it isnt normal for it to be audible

It does seem odd to be able to hear the brakes when they aren't being applied. I've used Axxis Ultimates before and Hawk HPS street pads, currently. Both generate more noise than factory pads (along with better braking) but I can only hear it when I'm actually braking. I can't actually hear anything when just cruising along or coasting, although I guess my catback exhaust and road noise might mask brake noise.

well im about a week from certified to do a brake job on any car in any shop so im tellin ya audible noise is not good and im sure he can hear this over his own road noise(or he wouldnt be mentioning it so it must be pretty loud) means something is not adjusted right im thinking that the rotors are warped and that the pistons might not have been pushed all the way back in this would make the pads hit the rotor in areas since the piston would be out to adjust for smaller (worn) pads. thats my two cents, also deending on the feel of the bake pedal there could be a problem there.

The rotors do not feel warped. Under light to heavy breaking, even on the track, I did not feel the pulsating pedal that is common with warped rotors.

Yes, I did push both of the pistons all the way back into the caliper before I installed the new pads.

No, I did not resurface the rotors. They were very even, smooth, and in overall good shape. But you are right, it is probably BEST to do a resurfacing if I were trying to be a certified, A++ mechanic that has a reputation to keep up with customers. :)

The noise is VERY SLIGHT. I have to go very slow, roll down the window, and pass an object that will reflect the noise, a fence, long wall, etc to hear the noise. Even then the noise is hardly noticeable, but came to my attention after switching to track pads.

I think that every thing is OK. I don't have any reason to believe the pads are glazed over or otherwise. But I should lube the caliper slider next time I do pads. I will be putting on the OEM pads soon so I will lube it then.

Will I need to bleed the brakes again after switching back to OEM pads? I think so...

i would recomend it (resurfacing that is), its porbly nothing at all since your windows are down and you need to be near a wall to hear it on my sh*ty chrysler i can here it and its normal pads on mine, though the car has loads of problems tht i havent got the money to fix. You should resurface the rotors though because enven if they are not warped they are worn and they are slicker than they should be, plus warping happens on the thousands of an inch scale meaning that you wont really be able to see it. i highly recomend resurfacing it at LEAST every other time especially when switching between pad types since the wear will be different., also resurfacing it will help with braking while the pads wear in( pads wont stop to well until at least 200 miles have been put on them though that distance may be shorter for race pads). as for bleeding it you wont really need to, the brake fluid should be fine even after a stint at the track. IF you knoticed some fade at the track though there could be air in the line or your fluid may have boiled and flushing and bleeding is a good idea at that point since the air once its there will always be there in the lines.

ok i dont know about the calliper build in the subaru, is it fixed: no sliding parts other than the pads?
is it a floating caliper: one side moves toward the inward pad and applys pressure to the outward surface?

if its fixed just get some graphite lube for the pad housing and lube that up nice this just makes it slide better to the disk.

if its a floating calliper then you ALWAYS lube up the sliding pins in the caliper, thats the pins that hold the "floating" side to the fixed side and allow the floating side to travel, they MUST be lubed and the rubber sleeve that they sit in should be replaced at a parts store that usualy runs 12 bucks for the rubber. if you dont want to replace them lube the crap out of those pins and push them in and out until it all slides nice and easy.

and when you put the caliper back on the assembly use white lock tite since its strong but not as strong as red, this makes the lock nice and strong but wont kill you to get them off next time you replace the pads.

oh and just a little info for everyone NEVER use air to clean out your brakes, the dust though it is not asbestos anymore is still NOT GOOD FOR YOUR LUNGS, use brake cleaner spray.

I believe it is a "floating caliper" on 02'-05' the WRX. Only 2 pistons on one side of the caliper that push toward the rotors.

I plan on getting separate rotors for track use to use in combination with track pads.

What lube should be used on the slider pins? Graphite or maybe white lithium grease?

there is a lot of info in this thread now.

thanks

If the rotors are resurfaced, have the service remove only a minimal amount as specified in the factory manual. The rotors need to retain a certain minimum thickness for optimum heat dissipation and strength. Not all shops or mobile services will pay attention to the thickness of the rotor and may casually grind away more from the surfaces than is absolutely necessary. You may end up with a beautiful-looking rotor that will run too hot during track days and cause the brake fluid to boil or break down the grease in the front wheel bearings.

I consider the rotors to be throwaway items (or recyclable) if the thickness falls to or below 0.866" as measured by a caliper - a ruler isn't precise enough. The factory specifies 0.945" as the standard value and 0.866" for the service limit for a 2002 WRX rotor thickness.

ok i dont know about the calliper build in the subaru, is it fixed: no sliding parts other than the pads?
is it a floating caliper: one side moves toward the inward pad and applys pressure to the outward surface?
<snip...>
and when you put the caliper back on the assembly use white lock tite since its strong but not as strong as red, this makes the lock nice and strong but wont kill you to get them off next time you replace the pads.
For the model year 2002 through 2005 WRX, they use a floating caliper as shown sitting on box in pic below. For 2006 through 2007, they switched to a 4-pot (piston) fixed caliper as shown installed on my car, which can also be retrofitted to earlier models. For the new MY2008 WRX, the pictures I've seen once again show a floating caliper, although it might be larger than earlier models.

Is Loctite® white-colored now? The type that could be disassembled with hand tools used to be blue-colored, but would dry out to whitish color.

locktite comes in different colors that indicate a different lock strenght, there is red and white red being really really strong and white being strong. the micormeter measures thickness in millimeters and the minimal is stated on the rotor you can take only so much off up to.015 or fifteen thousands to the minimal thickness, in FL the shops must pay attention to the minimal thinkness or its your butt on the line if anything happens.

graphite grease works well white lithium will work as well i believe i will have more info on that tomorrow though since i am not 100% sure.....once you have the rotor resurfaced...make sure there is a fine cut done...use a sander or jsut hand snd the surface in a circular patern the rotors were cut with the lathe in a direction....the direction that the pad moves on it...think of a ladder you cant clib up one with vertical rungs can you well pads will slow the rotor down less efficiently with just a resurfaced rotor so sand them to make it an undirectional cut.

ok as promised more info today....There are three good kinds of lubes to use one being the best and the other two being good to get the job done but may cause a problem with the rubber sleeve that encompasses the sliding pin.
GRAPHITE or ANIT LOCK- lube is a metalic lube that is great for sliding metal parts and is ok to use on the sliding pins though with old rubber sleeves it will irritate the rubber and make it swell causing the sliding side not to slide or make it very dificult to slide, the same goes for White Lithium, it works well but may cause the rubber sleeves to swell.
THE BEST TO USE ON SLIDING PINS is a silicon lubricant since it will NOT harm the rubber(though it is a good idea to replace them after a while)

White lithium can also melt and get on the rotors so make sure that you dont leave globs of it around the rotor.

Even more great info from Sti convert & Wingless Wonder, thanks.

Sti convert, why are you on a subaru forum when you drive a chrysler?
are you an ex subie addict who hangs around the forums? Thanks for the great info though, this will be a good reference for myself and those who search.

Wingless wonder, how do you like those 4 pots? I've been thinking about doing the upgrade. How much larger in circumference are the rotors that go with the calipers, same as the 2002 - 2005 WRX? Any significant weight difference, + or - a pound or two?

Wingless wonder, how do you like those 4 pots? I've been thinking about doing the upgrade. How much larger in circumference are the rotors that go with the calipers, same as the 2002 - 2005 WRX? Any significant weight difference, + or - a pound or two?
Use WRX rotor size - rotor replacement unnecessary unless you want/need new ones. I've replaced my rotors with factory-sized replacements, first with DBA one-piece, currently RacingBrake two-piece front rotors.

Have not tracked car with the 4-pots but should be fine. These calipers are more massive than WRX floating caliper. Have not weighed the WRX caliper but 4-pot weighs just over 10 pounds apiece. Figure a couple of pounds heavier than WRX pieces.

4-pots will not fit under OEM 16" WRX wheels or space saver spare tire. Must use aftermarket 17" or earlier 16" Impreza RS wheels.

RacingBrake.com offers their version of 4-pot caliper in aluminum alloy that is much lighter, retains front/rear brake balance, and uses factory pad sizing. Theirs also clears factory WRX wheels. Not inexpensive - pricing falls between the Subaru 4-pots ~$700 and a good big brake kit like the StopTech at around $1600.

If your eventual plans call for stickier tires, more track days, and a true big brake kit, then just skip the 4-pots. Some members have also performed Legacy GT front and rear brake swaps onto the early WRX. Bigger floating calipers and rotors compared with WRX.

im a convert lol when i get done with school im going to work with subaru and get an STi i just cant afford it yet they brought an STi into my shop at school and i fell in love and found this site researching the car.

if you convert to bigger and better braking systems convert the WHOLE system the stock master cylinder wont really do well with the new calipers.

oh yeah i used to only like domestics (though i drive a chrysler its mitsubishi buit...hate that company) so when i saw the sti i changed my mind its so sexy lol love these cars man just never knew it ....sorry for so many psosts im a little um tipsy well a lot tipy

axxis pads are noisey thats why he is noticing it more due to the agressive materials used to mfg the pads. dont worry about it.